Safety switch lock for railroads



es. 6, 3949 L. A. SMITH. 2,490,742

SAFETY SWITCH LOCK FOR RAILROADS Filed Oct. 2, 1944 2 Sheets-Sheet l Dec. 6, 1949 TH 2,490,742

SAFETY SWITCH LOCK FOR RAILROADS Filed Oct. 2, 1944 2 Sheets-Sheet 2 Patented Dec. 6, 1949 UNITED STATES PATENT OFFICE 2,490,742. SAFETY SWITCH LOOK FOR RAILROADS Lucian A. Smith, Glenburnie, Md.

Application October 2, 1944; Serial No. 556,836

4 Claims.

This invention refers to railroad track mech- '1 anism and more particularly to switch devices for same. It has among its objects to provide a switch that will be easier to repair when damoperatively locking theparts of the switch together in the position given by the train under the conditions stated. A further object is to have the lever and weight mechanism used for conventionally operating the rails at the switch rendered independent of the device yet working the signal through the device to show the proper indication, and true position of the switch. A

still further object is to have the mechanism of the device designed to automatically adjust, itself after its shearing safeguard has been used.

Other objects will become apparent as the invention is more fully set forth.

In the conventional type of switch used on railroads, the operation of the switch points are controlled by a weight and lever mechanism attached to a switch stand, which also controls the position of the signal light to which it is attached. The operation of a train running against the rear of the switch in locked position operates the mechanism so it shears or breaks off a lug or dog on one of its parts in the switch stand which renders it inoperative and allows the switch points to float loosely back and forth, in a direction opposite to the position shown by the signal lights thereby causing train wrecks until an operator arrives and takes the switch stand down and repairs it by putting its spare lug into commission. In this device the operation of its mechanism in the wrong direction changes the signal light to show the new position of the switch points and causes shearing of replaceable bolts or shearing pins which are readily accessible for replacing from the outside without dismantling the switch stand and without breaking the lug or dog in the switch stand.

When the replaceable bolts are sheared OH in this vice the operator raises the plunger, moves the leverarmand drops the new shearing'bolts or stand.

In' conjunction with the description herein appended, drawings are provided indicating a "structure of a switching device embodying this I invention as illustrated, in which:

Figure 1 is a plan View of the switching and signalling device embodying this invention;

along line 22;

Figure 3 is a plan view of the shearing and selflocking member shown in Figure 1;

4--4 of Figure 3; V Figure 5 is a sectional view taken along line 5-5 of Figure 3; I Figure 6 is a sectional view of Figure 3 taken along line 4-4 showing the pin sheared and the top and bottom plates moved until the choke bolt and lower plates together, and

Figure 7 is a sectional view taken along line of Figure 6.

Similar reference characters refer to similar ail-mans throughout the drawings.

Referring to the parts shown in the drawings l, 2, 3 and 44 respectively indicate the main track rails and the side track rails of a switch, in which 2 and 3 are those which are moveable by the switch. it-The moveable rails 2 and 3 are rigidly carried on an underplate 4 which is operated from the signal side of the tracks by a weighted lever mechanism 5 connected to it through a link 6, and top plate I. The top plate 1 slides on the underplate 4 it-and has a longitudinal bevelled slot 8 with end portions" I5 and enlarged circularly for purposes to be explained. Apair of bolt holes 9 are I located on the rail-side end portion [0 of the top plate I and are aligned with corresponding holes all in the underplate 4. These holes serve to take shear pins 12 that are sheared off when the underplate 4 is train operated against the stationary switch and locked weighted lever. These pins are preferably locked in place with cotter pins or sotherwise. The'top plate 1- is moveable with the under plate under normal conditions, being connected thereto by the shear pins I 2 and is guided by a choke bolt IS in its travel back and forth to throw the moveable rails in the conventional way. -This choke bolt is smaller at-its two middle portions I! so that portion can ride in the slot 8 under normal conditions. The upper portion of the choke bolt is larger and prevents it from passing down through the slot 8 until the pins I2 =ar sheared oiT and allow the underplate to move pins into position without touching the switch f Figure 2 is a sectional view of Figure 1, taken 3 Figure 4 is a sectional view taken along line .has dropped into position and locked the upper 3 until the large end portions or terminals l5 or 20 are reached, and align with the hole 45. The choke bolt through the action of springs 16 which press down on the cross bar it look the top and under plate together until new shear bolts are inserted.

The bar 18 is guided vertically on the posts IS on which the springs are mounted. The under plate 4 supports the posts. Suitable cross-ties 2| are used ordinarily =to hold the "switch unit and the various elements of thi's structure' in position, adjacent the tracks or rails operated by it. When the choke bolt is set in hole 2|! to the right in the drawing, the track to the left open and the train coming in the direction ofthe arrow shown in Figure 1 will take the through trackiioth'e-le'ft.

When in the opposite hole l5 the-trainwill take 4 with it through the operation of the posts l9 against them. The top plate 1 cannot move so the choke bolt l3 travels through its slot 8 until it reaches the large hole I5 or 20 at the terminus of same. The choke bolt actuated through the pressure of the springs I6 passes down into the holes l5 and 45 locks the top plate I and underplate 4 solidly together. The weighted lever mechanism cannot operate it, because its position isopposite to its proper movemen't to throw the "switch back to its original position. While the cross-plate or bar I8 was being moved, it rode ag'ainst the V-cam members 3| or riding plates 3i and was lifted over same and dropped on the the side track to the right. 'rne'nnss' is'hiligedly 7 plate "4 consists of an oiTsetpiece-lfi androdMi held together as indicated. The post. is supported on a base 2 l. Independently=connected to the top plate I isa switch-moving; mechanism 5 having alever 29 and weight 300i conventional form. This mechanism operates the moveable rails at the switch unit normally through links and gearing as shown-without passing through the signal and light. The move nent of the proper r'ails'however would tend to throw-the=weight and lever to its opposite position butcannotso the shear pins break. This would be the =case when-a train comes through the switch from one of'thebranch tracks when the switch is set for theother track. When the train comes from oneof the track in reverse, and the switeh'isopen to the other track/the wheelsof-thetrain will force the moveable rails of the first mentioned track. at "the switch, over to the open position 401 the track the train-is travelling from. In-Fig-ure 1, this'wo'uld be the trackleading from curvedrails; 3 and and would force over -the-rails -2 and 4 towards the left side or straight track 4 of the figure. 'Since the signal and lightindicate the position of the tracks in the first-placement loob ing in directionof arrow, the movement of-thejo rails 2 and 3 will'force the under plate '4 to the left also and "through'it and offset piece 26and rod '46 will turn the signal and light through one quarter of a revolution and indicatethe other signal, which will be red, looking in direction of'arrow, because the train ran throughthe rear on. the "red signal. At the same time theresistance ofiered by the weighted lever-mechanism 5 will cause the shear pins'to shear elf.

Summing the operation up, the-setting of the or weighted lever mechanism, -because' the switch (88 has left-same open. If the 'train came down the track to the right in reverse-it 'would -have "to force the rails 2 and '3 over toipermitit to pass through properly. When this occurs, the-underplate 4 moves to the left-withthese rails andtries To to operate the weight-lever-mechanism'i which resists, and causes the :stresson theshear pins I 2 and breaks them. The underplate-isthen -free from the top 1 plate and continues te-the -left carand cause wrecks.

arms drilled for bolts 32 to fasten same to one of the ties 2| and in the line of travel of the crossplate -18. Wh'enth'e 'ch'oke bolt is looked as stated abovegthe unit is in conditionto be repaired'but will hold switch inoperating position. Whilethe underplateis travelling under the action of the rails 'and' train and 'is moving the posts, crossplate andchoke bolt, itsconnections'to the signal and' lamp through theparts, and 25, 26 and46 cause it to turn same'to the position consistent with 'its n'ew position after the passage of the train in reverse. When the "signal shows this position, it warns the operators'to repair and resetit. The'movement of the -.rails 2 and 3when the :other'track is open,'by'a' train, to the right produces -a'sir'nilar movement of the parts only. in the opposltedirection. The underplate 4 is slidably attached to'track rails I and Mfby bolts '50 operatingin slots 5|.

While but one general form of the invention is zshown in the drawings and described i'n'the specificationa it is not desired to'limit this'applicationffor patent to the particular form or in any other way otherwise than limited by the scope thereof, as it is appreciated that other forms of construction could be made that would "use the same principles and come within "the scope of the "appended claims.

Having *thus'descri-bedthe invention, what is claimedis:

l. -A"railroa'd switch unit of the class described comprising in combination an 'underplate arranged for attachment to the moving switch points "of a railroad switch and for travelling therewith, a top plate mounted over the underplate, said top plate having a longitudinal slot therein and its'ter-miniienlarged at both ends.

a choke bolt having its shank in pluralsizes so it can-ride in the longitudinal'slot with the jportionor one size" therein and'move into a'nd'project through the terminii 'when'the portion of another 'sizeis -aligned therewith, means for normally holdingthe'choke bolt in a relatively stationary position-over the top :plate, shear :bolt's iorholdingthe underplate to the top plate for normal operation and to be sheared to loosen said platesfromone another when in abnormal operation, the movement 'ofthe' under-plate aft-er shearing of said shear bolts continuing and carrying the choke bolt therewith through the slot until a terminus is reached so it can lock therein with the switch points in the abnormal position derived from said'a-bnor'mal movement, and hold the top plate rigidlythereto so it will operate sequentially by the underplate'directly, a signal tievice connected withthe bottom 'plate ry e bo t l3 and-c o s-p a e. urban-la M adapted to change the indication thereof during the stroke of the bottom plate in coordination with the position of the points.

2. A railroad switch unit of the class described comprising in combination an underplate arranged for attachment to the moving switch points of a railroad switch and for travelling therewith, a top plate mounted over the underplate, said top plate having a longitudinal slot therein and its terminii enlarged at both ends, a choke bolt having its shank in plural sizes so it can ride in the longitudinal slot with the portion of one size therein and move into and project through the terminii when the portion of another size is aligned therewith, means for normally holding the choke bolt in a relatively stationary position over the top plate, shear bolts for holding the underplate to the top plate for normal operation and to be sheared to loosen said plates from one another when in abnormal operation, the movement of the underplate after shearing of said shear bolts continuing and carrying the choke bolt therewith through the slot until a terminus is reached so it can lock therein with the switch points in the abnormal position derived from said abnormal movement, and hold the top plate rigidly thereto so it will operate sequentially by the underplate directly, a signal device connected with the bottom plate adapted to change the indication thereof during the stroke of the bottom plate in coordination with the position of the points, and a riding plate arranged for the placement near the top plate for locking the choke bolt at the end of the stroke and permanently setting the :points in the position :derived from the abnormal movement, and the resulting shearing of said bolt.

3. A railroad switch unit of the class described comprising in combination an underplate arranged for attachment to the moving switch points of a railroad switch and for travelling therewith, a top plate mounted over the underplate, said top plate having a longitudinal slot therein and its terminii enlarged at both ends, a choke bolt having its shank in plural sizes so it can ride in the longitudinal slot with the portion of one size therein and move into and project through the terminii when the portion of another size is aligned therewith, means for normally holding the choke bolt in a relatively stationary position over the top plate, shear bolts for holding the underplate to the top plate for normal operation and to be sheared to loosen said plates from one another when in abnormal operation, the movement of the underplate after shearing of said shear bolts continuing and carrying the choke bolt therewith through the slot until a terminus is reached so it can lock therein with the switch points in the abnormal position derived from said abnormal movement, and hold the top plate rigidly thereto so it will operate sequentially by the underplate directly, a signal device connected with the bottom plate adapted to change the indication thereof during the stroke of the bottom plate in coordination with the position of the points, and a riding plate arranged for the placement near the top plate for locking the choke bolt at the end of the stroke and permanently setting the :points in the position derived from the abnormal movement, and the retry with one of said tracks to another, an over plate, shear pin means for rigidly attaching said over .plate to said underplate including a socket therein, a choke pin mounted on said overplate and held in that position by said underplate while the shear pin means is normally positioned in the underplate and overplate, said choke pin being subject to lock in said underplate when an abnormal movement of the points registered as aforesaid, breaks the shear pin and allows the underplate to move in relation to the overplate and permit the choke pin to move into said socket and stay therein in permanent connection therewith to hold the rail points inoperatively in the position derived from said abnormal movement, and mechanism for operating the switch unit when in normal setting.

LUCIAN A. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,048,480 Anderson Dec. 31, 1912 1,678,618 Preston July 24, 1928 2,283,645 Ne-whall Ma 19, 1942 

